With regards to the green stream on iVMS 4200 on a Mac, there's currently no support for H.264+ on the Mac OS version of iVMS 4200. If you try viewing a camera with H.264+ enabled, you'll either receive no stream at all or an unusable green stream. You actually can't enable or disable H.264+ via the remote config either. This can of course be resolved by disabling H.264+ on a camera, but that's obviously not ideal.
iVMS 4200 for Mac isn't updated anywhere near as frequently as it is for Windows, usually once or twice a year. The last we heard back in April was that an update to add H.264+ compatibility was due for August 2016.